Plant Sterols (Phytosterols) Proven to Improve Cholesterol
Multiple studies are now confirming that phytosterols from plants can significantly reduce LDL-cholesterol and VLDL-cholesterol – the “bad” cholesterols – as well as triglycerides. What are plant sterols? This article will explain, along with the findings on what dosages can reduce cholesterol, and how much it will reduce.
What is LDL-cholesterol?
LDL stands for low-density lipoprotein. The reason this, and very low-density lipoprotein (VLDL) is so bad is that they are easily oxidized.
Higher LDL-cholesterol levels have been associated with higher incidence of heart disease, atherosclerosis (hardening of the arteries), strokes and other cardiovascular issues. This is because LDL-cholesterol is less stable, and readily oxidizes. This oxidation produces free radicals that damage the walls of the blood vessels. This causes scarring, which tends to harden the arteries, as well as releases scar tissue into the blood. This release is what causes thrombosis.
Have you heard of plant sterols? These and a few other food compounds have been shown to reduce bad cholesterol levels. These include nuts, grains and fiber-rich foods, as we elaborate on below.
Research concludes plant sterols lower LDL-c
A number of studies have confirmed the success of plant sterols for reducing cholesterol over the past two decades. A consortium of 21 European universities and hospitals – called the EAS Consensus Panel – looked at the accumulated clinical research up until 2014. The panel found that consuming 2 grams per day of plant sterols and stanols reduced LDL-cholesterol levels by an average of 8-10 percent.
They also found that the same amount of phytosterols had the effect of reducing triglycerides by an average of 6-9 percent. Let’s look at a couple of these and other studies.
Clinical research on phytosterols
In a 2011 study published in the Journal of the American Medical Association, researchers from Canada’s University of Toronto and St Michael’s Hospital have found that people who ate diets rich in plant-based foods known for lowering LDL-cholesterol, including plant sterols, soy foods, nuts and plant-based fibers showed reductions in LDL-cholesterol by 13% after six months. The average reduction in LDL-cholesterol went from 171 mg/dL on average down 25 mg/dL to 156 mg/dL of LCL-c.
The study was published in month’s issue of the Journal of the American Medical Association.
The study followed 345 volunteers who either instructed to eat a low-saturated fat diet or were given specific dietary advice to eat certain foods known to lower cholesterol during clinic visits. Their LDL-cholesterol levels Those who eat the low-saturated fat diet showed a 3% reduction in LDL-cholesterol levels during the same period. Their levels reduced from the average of 171 mg/dL to 168 mg/dL.
The researchers also divided the specific-foods diet into two additional groups, one that was given two sessions of advice during the six months and the other, given seven clinical dietary sessions during the six months. These two groups showed little difference in their resulting LDL-cholesterol levels. The group given seven advice sessions had 13.8% average reduction in LDL-cholesterol, while the the group given two advice sessions showed an a 13.1% reduction in LDL-cholesterol.
The Canadian researchers concluded that:
“Use of a dietary portfolio compared with the low-saturated fat dietary advice resulted in greater LDL-C lowering during 6 months of follow-up.”
The “dietary portfolio” was the specific foods mentioned, offered within nutrition counseling sessions that taught the volunteers how to incorporate these LDL-cholesterol-lowering foods into their diets.
This result indicates that most people will adhere to diet advice when given occasionally as compared to frequently.
The overall result of the study, however, is consistent with the multitude of research. This has shown that plant sterols, cultured soy foods, nuts and high fiber foods specifically reduce LDL-cholesterol.
Plant sterols compared to statin drugs
A number of different studies have confirmed the findings above. Some of the research also quantified the ability of phytosterols in boosting the effects of statins.
But how about compared to statins?
A 2017 study from Brazil’s Pontificia University School of Medicine tested 41 patients with high LDL-c levels (over 70 mg/dL). They split them up into four groups. The control group remained on the same statin medication they were on. Another group was given the statin drug ezetimibe. Another group took both ezetimibe and the plant sterols. And another group took only the plant sterols.
After six weeks of treatment, the researchers found that the statin group’s LDL levels went up by an average of 9 percent. On the other hand, the LDL-c of those taking the plant sterols went down by 16.6 percent. In comparison, 10 milligrams of ezetimibe helped another group by 19 percent. And the patients that took both ezetimibe and plant sterols saw their average LDL-c levels go down by 27 percent.
We should note that ezetimibe’s adverse effects include muscle and joint pain, arm pain, stuffy nose, sinus pain, diarrhea and sore throat. Warnings include not taking ezetimibe if you have liver disease, are pregnant, breast-feeding.
This and other studies have noted that plant sterol – essentially foods – have no adverse side effects.
Plant sterols also reduce triglycerides
Many of the research studies on plant sterols have also found that phytosterols also reduce triglycerides. Triglycerides are also lipids that circulate in the blood. But they are different from cholesterol. Triglycerides carry fat in the blood, and higher levels have been linked with heart disease and hardening of the arteries.
The review of research through 2014 by the EAS Consensus Panel above found that 2 grams per day of plant sterols and stanols reduce triglycerides by between 6 and 9 percent within weeks.
What foods contain phytosterols?
Phytosterols include sterols and stanols. These are compounds found in most plant foods, including fruits, vegetables, seeds and nuts. The most common forms include stigmasterol, avenasterol, campesterol and beta sitosterol. These are the lipids that make up the cells membranes of plants. A healthy plant cell membrane made of these phytosterols helps protect the plant’s cells from becoming vulnerable to free radicals.
They also help reduce oxidized radicals in human nutrition because they attach and neutralize unstable lipids within the intestines.
Foods foods high in sterols include:
- fresh corn, with 952 milligrams per 100 grams
- rice bran, with 1055 milligrams per 100 grams
- wheat germ with 553 milligrams per 100 grams
- flaxseed with 338 milligrams per 100 grams
Nuts also have good sterol content. Cashews have 146 milligrams per 100 grams and peanuts have 206 milligrams per 100 grams. Other research has found that one Brazil nut a day will reduce cholesterol, and rice bran also reduces bad cholesterol.
Cold-pressed seed oils often contain greater levels because the sterols are typically left in the oil. But then again, it is not practical to consume large quantities of vegetable oils.
The average healthy diet might contain 200 to 300 milligrams per day. Vegan and vegetarian diets with plenty of healthy foods might contain up to 700 milligrams per day.
Note that these do not approach the 2 grams (2,000 milligrams) per day described in the research above. This means either eating a lot more of these sterol-rich foods or taking a supplement with concentrated amounts of phytosterols.
Lin Y, Koppenol WP, Knol D, Vermeer MA, Hiemstra H, Friedrichs S, Lütjohann D, Trautwein EA. Serum Concentration of Plant Sterol Oxidation Products (POP) Compared to Cholesterol Oxidation Products (COP) after Intake of Oxidized Plant Sterols: A Randomised, Placebo-Controlled, Double-Blind Dose‒Response Pilot Study. Nutrients. 2019 Sep 30;11(10). pii: E2319. doi: 10.3390/nu11102319.
Gomes GB, Zazula AD, Shigueoka LS, Fedato RA, da Costa AB, Guarita-Souza LC, Baena CP, Olandoski M, Faria-Neto JR. A Randomized Open-Label Trial to Assess the Effect of Plant Sterols Associated with Ezetimibe in Low-Density Lipoprotein Levels in Patients with Coronary Artery Disease on Statin Therapy. J Med Food. 2017 Jan;20(1):30-36. doi: 10.1089/jmf.2016.0042.
Gylling H, Plat J, Turley S, Ginsberg HN, Ellegård L, Jessup W, Jones PJ, Lütjohann D, Maerz W, Masana L, Silbernagel G, Staels B, Borén J, Catapano AL, De Backer G, Deanfield J, Descamps OS, Kovanen PT, Riccardi G, Tokgözoglu L, Chapman MJ; European Atherosclerosis Society Consensus Panel on Phytosterols. Plant sterols and plant stanols in the management of dyslipidaemia and prevention of cardiovascular disease. Atherosclerosis. 2014 Feb;232(2):346-60. doi: 10.1016/j.atherosclerosis.2013.11.043.
Jenkins DJ, Jones PJ, Lamarche B, Kendall CW, Faulkner D, Cermakova L, Gigleux I, Ramprasath V, de Souza R, Ireland C, Patel D, Srichaikul K, Abdulnour S, Bashyam B, Collier C, Hoshizaki S, Josse RG, Leiter LA, Connelly PW, Frohlich J. Effect of a dietary portfolio of cholesterol-lowering foods given at 2 levels of intensity of dietary advice on serum lipids in hyperlipidemia: a randomized controlled trial. JAMA. 2011 Aug 24;306(8):831-9.
Ågren, J. J.; Tvrzicka, E.; Nenonen, M. T.; Helve, T.; Hänninen, O. (2007). Divergent changes in serum sterols during a strict uncooked vegan diet in patients with rheumatoid arthritis. British Journal of Nutrition. 85 (2): 137–9. doi:10.1079/BJN2000234